When Old Becomes New

GT Metal Products (Edmonton, Alberta, Canada) is a custom metal fabrication job shop that manufactures power distribution panels, grain hopper bottoms and aeration tubes, stair cases, hand rails and steel structures, computer module consoles, and complete communication and electrical cabinets.

The shop has a wide range of capabilities that include CNC forming, plasma and laser cutting, robotic welding, rolling, shearing, punching and drilling, as well as drafting and engineering design. Their extensive fabrication capabilities range from the design, build and delivery of a single custom part to large scale mass production that requires multi-process manufacturing.

GT Metal Products found that, to be competitive in the market, the pressure was on to supply a far higher level of precision cutting than had previously been required. The shop was looking for ways to ensure the proper angularity of cuts and accuracy of parts to customer drawings. They had to maintain required tolerances and make sure parts were straight and smooth, with few customer rejects.

OUT WITH THE OLD PLASMA SYSTEM
In response to customer demand for more precise cutting than could be obtained with their older plasma system, the company replaced the old system with two Mazak STX510 MkII 2.5 kW CO₂ lasers a few years ago. They originally ran two CAM systems to drive the lasers, but experienced problems that made them consider alternative solutions.

“Previously we could only specify one cut condition per thickness, which gave us quality issues,” explains production manager Dustin Sim. “We were also looking to find a faster way to nest parts and reduce material waste. Based on our previous CAM experience and the ability for the software to allow for multiple cut conditions per thickness, we selected JETCAM (Monte Carlo, Monaco) and opted for their High Performance Nesting module from to maximize efficiency and material usage.”

Two licenses of JETCAM Expert were installed in May 2009, one with the High Performance Nesting module. This configuration allowed two programmers to design parts and one machine to be used for generating highly optimized nests. The staff was initially trained, but were then able to learn the system independently due to the additional training material that was provided.

After installation a number of benefits immediately came to light. Programming time was halved as processes took much less time than the previous systems due to many of the processes becoming automated. Once profiling information is applied to each part it is immediately available for each machine, with any updates reflected automatically on any nests.

Nesting time was reduced an astounding 90 percent as users began to simply queue up all parts to be nested for a given material and thickness, and specify an amount of time that the nester can run for (which can be overnight to allow the system to consider the most optimized nesting options) and generate NC code. Machine cycle time also saw a 20 percent improvement due to optimized lead-ins, common line cutting, path optimization and finishing cut sequences all playing a part.

Material utilization improved by 25 percent, not only because of the newly optimized nests, but from the ability to store and re-use remnant sheets efficiently. “We can quickly queue up multiple jobs and nest them together for efficiency,” notes Sim. “When you add up all of the savings from these process gains, we paid for the software system in just two months.”

Support requirements had previously taken up more staff time because one of the older CAM nesting systems took considerably more time than the other one. The company converted their two licenses to a server-based floating setup that allows several PCs to have the software installed and for two to run concurrently. “The JETCAM software is faster and much more flexible than all of the previous systems we’ve used. It excels in material utilization and generating optimized NC code.”

But unfortunately, while the new CO₂ lasers were indeed able to deliver on their high precision claims, their slower cut speeds seriously disrupted production flow and limited business growth. Operating and maintenance costs for the lasers were also higher and the thickness range was affected. The CO₂ lasers reached their limit of effectiveness at thicknesses up to ¾ in, so the plant was faced with the need to turn away customer requests for cutting of over ¾ in mild steel.

In addition, the shop found that the laser tables, which measured 5 ft by 10 ft, resulted in plate size limitations because demand was increasing for cutting 6 ft by 24 ft plate. Since increased cutting time was crucial to its continued growth and success, the company went looking for a cutting solution that would offer the fast cutting speeds and low maintenance costs typically associated with plasma, combined with a cut quality comparable to laser.

Their goal was to find a tool that could handle the backlog that had been building up on the lasers,  ensure parts flow to their seven full-time welders, and provide more quoting and business growth opportunities.

IN WITH HIGH DEFINITION PLASMA CUTTING
The shop owner worked with Pinnacle Industrial Automation Inc. (Mississauga, ON), the OEM that originally sold the company the CO₂ lasers, to find a plasma cutting solution that would offer the necessary productivity improvements along with a cut quality comparable to laser.

The integrated plasma cutting system that was recommended features an ultra-precise table motion capable of providing a near laser quality cut. This system, built by Hypertherm, Inc. (Hanover, NH), expands GT Metal Products’ already extensive offerings beyond the limitations of the lasers and enables greater flexibility in quoting, materials use, and production, with lower operating and maintenance costs.

The plasma cutting system uses a HyPerformance® Plasma HPR130XD® to deliver near laser cut quality with minimized operating and maintenance costs. An EDGE®Pro CNC and ArcGlide THC create Rapid Part technology that significantly improves productivity without operator intervention. It has increased the plasma cut speed up to three times over the CO₂ laser.

The programmer uses ProNest2010 nesting and process optimization software to more easily monitor material usage and minimize scrap. The system applies True Hole™ technology to minimize drilling and secondary operations by automatically delivering bolt-quality holes. “HyPerformance Plasma cuts at lower cost, at higher speeds, with greater quality,” comments Dennis Berreth, the owner of GT Metal Products. “We have gone from cutting at 26 ipm with the lasers to 80 ipm with the plasma, and drilling has been minimized due to this technology.”

The addition of this cutting machine immediately allowed the shop to reduce their operating expenses by eliminating the second shift and returning to the one-shift model that decreased heating and cooling, supervision, and overtime costs.

The nesting software helps their programmer monitor material usage and minimize scrap, giving the shop greater flexibility with quoting projects because they can offer both laser and plasma pricing. “With quotes 30 percent less than laser quotes for the same job, plasma is often better than the job requires, so we are able to give our customers the choice, as well as the option to save money,” explains Berreth.

Reduced maintenance costs have proven to be a benefit as well. “The plasma system is much easier to maintain and requires less than half the time,” notes Berreth. The material range of the HPR130XD has also expanded the services the company offers by allowing them to cut A516 (PVQ 516-70) steel plate, abrasion resistant (AR) steel, and quenched and tempered (QT) steel plate. Any material with scale or rust now automatically goes to the plasma. “We don’t cut a lot of it, but to keep our customers happy we can cut it when we need to, and that is important,” smiles Berreth.

TWO BETTER THAN ONE
Now the company uses both technologies to give customers the full range of thickness with the level of detail needed for the particular project or application. They offer laser cutting for fine features and extra detail on thinner materials used for precision parts with tight tolerances, very thin (less than 10 ga) stainless steel, or for parts with lots of holes that are very close together.

For the larger, thicker or longer pieces, like those for drilling rigs, construction or agricultural installations, the plasma cutting tool is ideal. Since the high definition plasma offers excellent cut accuracy at about 30 percent less cost, some customers who originally requested laser cutting may opt for plasma when they see the results.

Having both technologies in-house avoids the problems frequently associated with subcontracting out jobs. GT Metal Products can control the quality and doesn’t have to deal with labor costs and safety risks of loading, unloading, and inspecting material. Transportation of parts slows down turnaround time, and fuel and shipping costs can mount up. Having both cutting tools in-house removes all of these variables and allows the shop to turn around work more quickly and avoid being at the mercy of a subcontractor’s schedule.

“Our integrated plasma cutting solution delivers increased productivity with up to three times improvement in cut speed over CO₂ lasers,” states Berreth. “We can now offer more cutting time and provide what our customers need at the quality and price they need it.”

GT Metal Products, 5616-103 Street (Gateway Boulevard), Edmonton, Alberta, T6H 2H5 Canada, 780.-434.-8721, Fax: 780-437-5960, sales@gtmetal.com, www.gtmetal.com.

JETCAM International s.a.r.l., “Millenium” 9C, 9 Boulevard Charles III, Monaco, Monte Carlo 98000, +44 (0) 870 760 6469, www.jetcam.com.

Hypertherm, Inc., PO Box 5010, Hanover, NH 03755, (603) 643-3441, Fax: (603) 643-5352, technical.service@hypertherm.com, www.hypertherm.com.

Pinnacle Industrial Automation Inc., 39-5359 Timberlea Boulevard, Mississauga, ON L4W 4N5, 905-212-1096, Fax: 905-212-1097, www.pinnacle-ia.com.